1. Field of the Invention
The present invention is related to an access node (e.g., DSLAM) that incorporates an enhanced rapid TV channel changing functionality/enhanced BTV server which dynamically selects a set of TV channels from a multicast TV stream using past TV channel clicking statistics and then stores the selected TV channels so it can respond to a TV channel change request that is subsequently received from an attached STB.
2. Description of Related Art
The following abbreviations are herewith defined, at least some of which are referred to in the ensuing description of the prior art and the present invention.    BTV Broadcast Television    BW Bandwidth    CO Central Office    CPE Customer Premises Equipment    DSL Digital Subscriber Line    DSLAM Digital Subscriber Line Access Multiplexer    HDTV High-Definition Television    HSI High Speed Internet    Mbps Mega-Bits-Per-Second    PIP Picture-in-Picture    RCC Rapid Channel Change    SDTV Standard Definition Television    STB Set-Top Box    TV Television    VHO Video Hub Office    VoD Video-on-Demand    VoIP Voice-over-Internet Protocol
Telecommunication service providers plan to use a transport network to offer triple-play services, which include video (BTV), voice (telecommunications) and data (Internet) to homes via DSL phone lines. To accomplish this, the transport network needs to be able to provide a BTV service which has an effective rapid TV channel change functionality. Because, if it does not, when a user who is watching TV decides to change the TV channel then that person will likely experience an undesirable delay before the new TV channel is displayed on their TV. Several solutions have been offered to help address this TV channel changing latency problem. One of these solutions is described next with respect to FIG. 1 (PRIOR ART).
Referring to FIG. 1 (PRIOR ART), there is a block diagram illustrating the basic components of a traditional transport network 100. As shown, the traditional transport network 100 includes a VHO 102, a CO 104, an access node/DSLAM 106 (one shown) and STBs 108. In operation, the VHO 102 multicasts a set of TV channels 109 via the CO 104 and access node 106 to the STBs 108. Then, a user interfaces with their STB 108 (e.g., STB 108a) and selects one of the multicast TV channels 109 to watch on their TV (not shown). The user may want to watch another TV channel after a period of time and when this happens they input a TV channel change request 107 into their STB 108a. The STB 108a forwards the TV channel change request 107 to the VHO 102. Upon receiving the TV channel change request 107, the VHO 102 and in particular the rapid TV channel change functionality 110 therein unicasts the requested TV channel 111 directly to that STB 108a. 
This solution enhances the television viewing experience by enabling a user to rapidly switch TV channels. However, a main drawback of this solution is that a large amount of bandwidth on a feeder link 112 (which also transmits PiP, VoD, VoIP and HSI traffic) between the CO 104 and the access node 106 is needed to unicast TV channels 111 to individual STBs 108. The bandwidth on a link 114 between the VHO 102 and CO 104 is also increased. To help alleviate this problem, the access node 106 can be configured to implement its own rapid TV channel change functionality as described next with respect to FIG. 2.
Referring to FIG. 2, there is a block diagram illustrating the basic components of a transport network 200 which has an access node 206 that is configured to implement a rapid TV channel change functionality 210 as described in the co-assigned/co-filed U.S. patent application Ser. No. 11/311,046. As shown, the transport network 200 includes a VHO 202, a CO 204, an access node/DSLAM 206 (one shown) and STBs 208. In operation, the VHO 202 multicasts a set of TV channels 209 via the CO 204 and access node 206 to the STBs 208. The access node 206 implements a rapid TV channel changing functionality 210 (integrated BTV server(s) 210) which: (1) stores “popular” TV channels 211a selected from the multicast TV channels 209; and (2) unicasts one of the stored “popular” TV channels 211a to a particular STB 208 (e.g., STB 208a) in response to receiving a TV channel change request 207 (e.g., TV channel change request 207a) from that STB 208a. It is not practical for the rapid TV channel changing functionality 210 to store all of the multicast TV channels 209.
The integration of a rapid TV channel change functionality 210 within the access node 206 effectively reduces a substantial amount of bandwidth on the feeder link 212 between the CO 204 and the access node 206. This reduction of bandwidth on the feeder link 212 can save a telecommunications service provider millions of dollars in transport costs a year. However, if the access node 206 has not stored a TV channel 211b which is requested by a STB 208 (e.g., STB 208b) via an incoming TV channel change request 207 (e.g., TV channel change request 207b), then the access node 206 needs to forward the TV channel change request 207b to the VHO 202. Thereafter, the VHO 202 and in particular a rapid TV channel change functionality 214 therein needs to unicast the requested TV channel 211b directly to that particular STB 208b. If this happens, then additional bandwidth will be used on the feeder link 212 between the CO 204 and the access node 206. The use of additional bandwidth on the feeder link 212 is not desirable. As such, it is important that the access node 206 and in particular the rapid TV channel change functionality 210 therein determines and stores the “right” TV channels to minimize the need to forward a TV channel change request 207b to the VHO 202. This need and other needs are satisfied by the present invention.